Method and apparatus for manufacturing envelopes, bags and like objects



June 1, 1965 p zscl- 3,186,315

METHOD AND APPARATUS FOR MANUFACTURING ENVELOPES BAGS AND LIKE OBJECTS Filed April 24, 1963 2 Sheets-Sheet 1 SCH R MANUFACTURING IKE OBJECTS June I, 1965 B. PAHLlTZ METHOD AND APPARATUS F0 ENVELOPES, BAGS AND L 2 Sheets-Sheet 2 Filed April 24, 1963 United States Patent 9 Claims. (or. 93-62) The present invention relates to a method and an apparatus for manufacturing envelopes, bags and similar objects.

There are already known methods in which, in one continuous process, envelopes, bags or similar objects are cut, printed, gummed, dried, then folded and glued, all on one machine from one reel, whereupon the flap is folded. In this method, the closing flap faces forwardly in the direction of movement, and the gumming is effected by means of a spreading roller. In the known method, this sequence is necessary, since for the gumming a subdivision of the individual cuts is required which is possible with known means, namely with conveyor bolts running at different speeds, only with paper with the same thickness so that the staging and the gumming itself must be effected before the folding and gluing of the cuts. Thus, the cuts must be conveyed in the unfolded state through the machine up to the completed drying; this requires equipment adapted to receive the unfolded sections, necessitating thereby larger arrangements and more costly installations than would be the case with an already folded and glued envelope. However, with all these known arrangements, staging is possible only with unfolded cuts. With workpieces of different thicknesses, that is. with folded and glued envelopes, the conventional staging method by conveying means with different speeds fails, since these envelopes have three different thicknesses, namely, the single layer of the closing flap; secondly, the double layer of the pocket; and finally, the triple layer of the folded side members, so that the stiffness of the envelopes and therewith also the resistance to staging becomes greater. Known methods are incapable of staging or stacking the scored envelopes with sufficient accuracy so that the surface to be gummed is always exposed at the same width.

The present invention relates to a method which avoids the disadvantages of known methods and offers an additional further advantage. According to the method of the invention, the cut envelopes are first folded and glued and are then lifted, with the closing flap facing rearward-1y in the direction of movement, for stacking onto a higher conveyor section running at reduced speed, this reduction in velocity being such that the stacked envelopes overlie one another in such manner as to expose the flap sections to be gummed, whereupon the gumming is effected by means of a rubber roller revolving at a speed corresponding to the speed of the slower conveyor section, and finally the closing fiap is folded after the gum has dried. According to the method of the invention it is possible to take the cuts or blanks continuously from a roller and to fold and glue them after printing on one or both sides, and finally to apply the gum to the envelopes thus formed. This is rendered possible by the transfer to an elevated conveyor where reliable staging is effected by dis-posing the following envelope under the closing flap of the preceding one during the transfer of the latter onto the slower running conveyor. This machine may achieve without difliculties an accurate and constant staging in spite of differences in the thickness of the paper. Another advantage resides in the possibility of using the machine operating according to this method both for the manufacture of envelopes equipped with triangular flaps and with self-closing flaps, as will be explained further below.

The machine operating according to the method of the invention comprises a pair of rollers in the delivery path, the lower roller having on its surface an axially parallel, radial abutment face and a milled recess with a face normal thereto, the height of the radial abutment surface corresponding to the lifting distance of the conveyor track. According to the invention, the delivery roller comprising the milled recess is associated with a lever actuated by a cam plate as a function of the delivery speed, which lever lifts the end of the closing flap when the envelope passes through the pair of rollers. According to a further feature of the invention, the individual envelopes are arranged on the conveyor with such a distance between their leading edges that this distance corresponds to the circumference of the delivery rollers having the milled recess. According to yet another feature of the invention, the pair of rollers receiving the envelopes from the recessed roller revolves at a lower speed, determining the width of the gumming, and is adjustable in its distance relative to the first roller in accordance with the size of the envelopes to be made.

The delivery of an envelope to the higher conveyor is effected by a lifting roller equipped with a recess. The individual envelopes are positioned on the lower conveyor at intervals, corresponding to the circumference of the lifting roller. In addition, the envelopes are arranged on the lower conveyor so that an envelope is always supplied to the lifting roller at the moment at which the abutment face of the milled recess is in the vertical top position. An envelope seized by the lifting roller in this position is lifted by the edge of the face of the recess, normal to the abutment face during the rotation of the roller and delivered to the upper conveyor, where it is gripped, as known per se, by a pair of rollers driven through a transmission, at lower speed. The distance between this pair of rollers and the lifting roller is adjustable to allow the machine to be used for various envelope sizes. The distance between the two pairs of rollers is practically equal to the total length of the envelope viewed in the direction of movement so that the end of the flap of the envelope gripped by the slower pair of rollers overlies the leadingedge of the following envelope which enters at faster motion into the recess. When the slower rollers have moved the first envelope by a distance corresponding to the width of the gumming, the leading edge of the following envelope is engaged by the slower rollers, and the staging is thus effected at accurate and constant intervals.

Thus, the machine according to the invention may be used for manufacturing any size envelope, provided that its delivery length is smaller than the circumference of the lifting roller. In order to support the staging, the lifting roller is associated with a lever engaging thereinto and moved by, say, a cam plat-e intermittently so that it lifts the end of the closing flap gripped by the lifting roller before a new envelope enters into the lifting roller recess.

According to the invention, the staged or shingled envelopes are gummed by means of an application roller, supplied with adhesive as known in the art and transferring the same to the envelope by rolling thereon. To this end, the application roller moves at exactly the speed of the delivery conveyor. The advantage of using such an application roller is that a coherent, uniform layer of gum is applied; such uniformity is usually impossible of attainment by means of arrangements using brushes, because here there are formed striped, grooved or thinner sections or the like. However, another and decisive advantage of this application roller is that the method according to the invention may also be used for the steadily more popular self-sealing or pressure-sealing type of envelopes. These self-sealing envelopes have a flap in two parts, comprising a top flat forming part of the front side of the envelope and gummed on the reverse side, and a bottom flap, connected to the back of the envelope and gummed on the underside. 'Both flapsare practically rectangular and extend over the entire width of the envelope. The simultaneous gumming of both flaps may be effected only if the blanks have been folded and glued at the sides, so that the method of the invention may be used without further modification also for this purpose. The gumming substance is a latex rubber which is adhesive only when making contact with a surface which has also been gummed. In order to close the envelope, the lower flap is opened and the top flap closed, causing both flaps to make contact with one another. After the application of the gum, both parts must be folded over. When this gum is applied by brushing, there is formed necessarily a closed film of glue, covering both the lower and upper flaps; this film may cause the edges of the upper and lower flaps to adhere together after drying so that the necessary folding can no longer be effected on the machine and unusable envelopes are supplied. In order to ensure the reliable folding of the lower flap it is necessary for the gumming to be interrupted by a narrow, ungummed strip between the upper and lower flaps so as to prevent adhesion between these twoparts. This interrupted gumming is naturally impossible where brushing is used, but may be effected by means of an application roller operating according to the method of the invention. For this purpose, the gum-application roller, revolving according to the invention at the slower speed, has on its circumference axially parallel groovelike recesses, applying a layer of gum the width of which is determined by the width of the grooves so that the interruptions are always located between two partial flaps of envelopes. The width of thegrooves corresponds to the width of the gum-free strip between upper and lower flaps, while the mutual distance between the grooves corresponds to the width of gumming of an upper flap and an adjacent lOWer flap of a following envelope.

The method according to the invention may therefore be used at choice both for the manufacture of conventional envelopes with triangular flaps, and for self-sealing envelopes, requiring only an application roller with continuous surface to be exchanged against a grooved application roller. Since the delivery speed of the envelopes and the speed of the application roller are always the same, and the staging is effected accurately by the lifting roller, the gum-free gap between top and bottom flaps will always be in the correct position with each envelope.

The accompanying drawing show an embodiment of a machine operating according to the method of the invention. In the drawing:

FIG. 1 is a diagrammatic side-elevational view of the machine,

FIG. 2 is a plan View of a staged self-sealing envelope, and

FIG. 3 is a perspective view of an open self-sealing envelope.

In the fragment of the machine shown in FIG. 1, the individual folded and glued envelopes arrive in the direction of the arrow on the conveyor 1, with their flaps trailing, the distances between the leading edges of the envelopes being equal'to the circumference of the lifting roller 3. The machine is so aligned that, in the position according to FIG. 1 of the lifting roller 3, the leading edge of an envelope abuts against the face 5 of the recess 4. The lifting roller revolves in a clockwise direction, and lifts the envelope in the recess 4 to the conveyor 6 v/here it is delivered between the hollers 2, 3 with the velocity of the conveyor 1 to the pair of rollers 7, 8. The spacing of the pairs of rollers 2, 3 and 7, 8 along the transport path may be adapted to the size of envelope to be manufactured. To this end, the pair of rollers 7, 8 is mounted on a lever 9, pivotable about a pivot 10 and The end of the closing flap of the envelope projects into the recess 4. Previously, the lever 14 has been raised and lifted the end of the flap so that the folowing envelope engages reliably under this flap. The faster revolving pair of rollers 2, 3 now pushes the next envelope so far under the preceding one that only the edge to be gummed is exposed. The envelopes staged in this manner pass at slower speed the pair of rollers 7, 8 and are engaged by the pair of rollers 15, 16, revolving at the same speed, of which the roller 15 is a gumming roller, supplied through an arrangement 17 with glue. The staged and gummed envelopes are then delivered to the conveyor 19 and pass to the drier.

For the manufacture of self-sealing envelopes, a roller 15 with circumferentially arranged grooves 18 is used. FIGS. 2 and 3 show, by way of explanation, such a selfsealing envelope. 7 FIG. 2 shows two stacked and offset envelopes 20 and 21. The envelope 21 is located under the envelope 2% The envelope 20 has'a lower flap 22 and an upper flap 23, between which there is an ungummed gap 24. The envelope 21 ha a lower flap 25, an ungummed gap 27, and an upper flap 25. The width of the gap 24 or 27 corresponds to the width of the groove 18, whilst the distance between two grooves is equal to the distance between the gaps 24 and 27. The finished, gummcd and dried envelopes travel then to a folding apparatus, where the lower flaps 22 and the upper flaps 23 are folded by What I claim is: I

I. In a method of manufacturing self-sealing envelopes wherein a blank is formed with an open edge and at least one closing flap, said flap extending beyond said edge, the improvement which comprises the steps of advancing a succession of said blanks along a transport path with the flaps of said blanks trailing; shingling said blanks by successively disposing successive blanks beneath preceding blanks with the flap of each successive blank and 21 marginal zone thereof adjacent its respective open edge substantially contiguous with the superposed flap of the preceding blank; and applying a contact adhesive to said flaps and zones by rolling over said blanks at the speed thereof an adhesive-applying closed surface formed with discontinuities extending parallel to said open edges and substantially registering therewith.

2. In a method of manufacturing self-sealing envelopes wherein a blankis formed with an open edge and at least one closing flap, said flap extending beyond said edge, the improvement which comprises the steps of advancing a succession of said blanks along a transport path with the flaps of said blanks trailing; shingling said blanks by successively disposing successive blanks beneath preceding blanks with the flap of each successive blank and a marginal zone thereof adjacent its respective open edge substantially contiguous with the superposed flap of the preceding blank; and applying a contact adhesive to said flaps and zones by rolling over said blanks at the speed thereof an adhesive-applying closed surface formed with discontinuities extending parallel to said open edges and substantially registering therewith and spaced apart by equal distances corresponding to the combined width of a marginal zone of each blank and the flap of a preceding blank whereby a gap in the adhesive is maintained between the adhesive applied to each flap and that applied to the marginal zone of a respective blank.

3. In an apparatus for the manufacture of self-sealing envelopes, in combination, first transport means for advancing a section of blanks having each at least one open edge and at least one closing flap extending beyond said 5 edge at a first speed with the flaps of said blanks trailing; second transport means forwardly of said first transport means in the direction of travel of said blanks and operable at a lower speed; shingling means between said first and second transport means for staging said blanks by I transferring said blanks from said first transport means to said second transport means with each successive blank overlying a preceding blank and having its respective flap and a marginal zone adjacent its open edge extending rearwardly beyond the preceding blank substantially contiguously with the superposed flap thereof; and gumming means along said second transport means and including an adhesive-applying closed surface rollingly engageable with said blanks and operable at the speed thereof while being formed with discontinuities extending parallel to said open edges and substantially registering therewith whereby a gap in the adhesive is maintained between the adhesive applied to each flap and that applied to the marginal zone of a respective blankt 4. The improvement defined in claim 3 wherein said closed surface is formed on a cylindrical roller overlying said second transport means, said discontinuities consisting of circumferentially equally spaced axially extending grooves formed in the face of said roller.

5. The'improvement defined in claim 4 wherein the circumferential spacing of said grooves is equal to the combined width of said marginal zone and said flap of each blank.

6. The improvement defined in claim 3 wherein said shingling means includes an elevating roller which said transport path intersects along a secant of said roller,

, .3 said roller being provided with a generally radial abutment face'defining an L-section recess adapted to receive the leading edges of blanks displaceable along said transportpath'and elevating said leading edges upon rotation of said roller above said transport path, said second transport means being disposed above said transport path by a distance substantially equal to the height of said abutment face. i

7. The improvement defined in claim 6 wherein said blanks have leading edges spaced along said first transport means by a distance corresponding substantially to the circumference of said elevating roller. 1

8. The improvement defined in claim 7 wherein said second transport means includes a pair of rollers operating at a peripheral speed less than the peripheral speed of said elevating roller for receiving between them the blanks elevated to said second transport means by said elevating roller, further comprising means for adjusting the distance between said path of rollers and said elevating roller.

9. The improvement defined in claim 6 wherein said shingling means includes a lever synchronized with said elevating roller for lifting the flap of each blank as it is elevated by said roller thereby enabling the disposition of the leading edge of a successive blank therebelow.

' References Cited by the Examiner UNITED STATES PATENTS 2,851,934 9/58 Heywood 9362 FRANK E. BAILEY, Primary Examiner. 

3. IN AN APPARATUS FOR THE MANUFACTURE OF SELF-SEALING ENVELOPES, IN COMBINATION, FIRST TRANSPORT MEANS FO ADVANCING A SECTION OF BLANKS HAVING EACH AT LEAST ONE OPEN EDGE AND AT LEAST ONE CLOSING FLAP EXENDING BEYOND SAID EDGE AT A FIRST SPEED WITH THE FLAPS OF SAID BLANKS TRAILING; SECOND TRANSPORT MEANS FORWARDLY OF SAID FIRST TRANSPORT MEANS IN THE DIRECTION OF TRAVEL OF SAID BLANKS AND OPERABLE AT A LOWER SPEED; SHINGLING MEANS BETWEEN SAID FIRST AND SECOND TRANSPORT MEANS FOR STAGING SAID BLANKS BY TRANSFERRING SAID BLANKS FROM SAID FIRST TRANSPORT MEANS TO SAID SECOND TRANSPORT MEANS WITH EACH SUCCESSIVE BLANK OVERLYING A PRECEDING BLANK AND HAVING ITS RESPECTIVE FLAP AND A MARGINAL ZONE ADJACENT ITS OPEN EDGE EXTENDING REARWARDLY BEYOND THE PRECEDING BLANK SUBSTANTIALLY CONTIGUOUSLY WITH THE SUPERPOSED FLAP THEREOF; AND GUMMING MEANS ALONG SAID SECOND TRANSPORT MEANS AND INCLUDING AN ADHESIVE-APPLYING CLOSED SURFACE ROLLINGLY ENGAGEABLE WITH SAID BLANKS AND OPERABLE AT THE SPEED THEREOF WHILE BEING FORMED WITH DISCONTINUITIES EXTENDING PARALLEL TO SAID OPEN EDGES AND SUBSTANTIALLY REGISTERING THEREWITH WHEREBY A GAP IN THE ADHESIVE IS MAINTAINED BETWEEN THE ADHESIVE APPLIED TO EACH FLAP AND THAT APPLIED TO THE MARGINAL ZONE OF A RESPECTIVE BLANK. 